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Accounting for Stock-Based Compensation - Schedule of Share-based Payment Awards, Stock Options, Valuation Assumptions (Details) - Employee Stock Option
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility 73.50% 68.40%
Expected term 6 years 5 years 7 months 6 days
Risk-free interest rate 1.00% 2.60%